The present invention relates to a management method for video data, which are data to be used in the computer handling of pictures recorded in recording apparatuses such as video taperecorders, and to a video data management apparatus using this video data management method.
To begin with, the terms used in this specification will be defined.
A frame means a still picture.
A video source is pictures themselves recorded on a video tape or video disk, or in an optical disk apparatus or a hard disk apparatus or the like. A video source consists of a set of frames.
Video data are data designating useful parts of a video source. For instance, they designate the parts to be cut out when editing a video source. Video data are also used for specifying the positions and configurations of objects which are to appear in a frame.
Application data result from the editing and modification of a video source as indicated by video data. Application data are usually referred to as video data. Thus the term "video data" can be used in two different senses. In this specification, in order to make the meaning of "video data" unmistakable, an edited video source will be referred to as application data.
Index data are a sort of video data. They designate a range in a video source. Typical index data are a pair of a start frame number and an end frame number. Frames from one designated by a start frame number and another designated by an end frame number constitute the range designated by index frame.
Next will be described the pertinent prior art.
One example of conventional video data management method is disclosed in a paper by Wendy E. Mackay and Glorianna Davenport entitled "Virtual Video Editing in Interactive Multimedia Applications", published in Communications of the ACM, July 1989, vol. 32, No. 7, pp. 802-810. Lines 16 to 21 of the right column, page 802, of this paper constitute a statement to the effect that data corresponding to a start frame number and an end frame number are accumulated as video data. Thus, according to the method described in this paper, index data for editing a video source into application are stored for all application data.
This video data management method according to the prior art involves the problem that an enormous volume of video data has to be accumulated. This problem is explained by way of an example.
Suppose that, application data "A" is composed of some parts of a video source joined together, and application data "B" is composed of some parts of application data "A". In this case, most parts of application data "B" overlap video data of application data "A". However, by the aforementioned method according to the prior art, video data for application data "A" and video data for application data "B" are separately accumulated, resulting in a tremendous volume of video data that have to be accumulated.